Devices for the production of multicomponent fibers are known from the prior art (U.S. Pat. No. 6,478,563 B1, U.S. Pat. No. 6,491,507 B1). With these known devices, two inflow channels, in which in each case a melt flow of one component for bicomponent fibers is conducted, run entirely in the middle nozzle block and along the edge of the middle nozzle block respectively. With these known devices, the thermal separation of the two melt flows represents a problem. In other words, as a rule there is mutual interference between the two hot melt flows. This leads to irregular or inhomogeneous temperature distribution, which in turn results in disadvantageous impairment of the flow consistency of the melts. These problems are particularly marked when the melting points of the two components exhibit significant differences, such as in excess of 50° C. This applies, for example, if one component is a polyolefin, such as polypropylene, and the second component is a polyester, such as polyethylene terephthalate (PET).